Half to a



(No Model.) 2 Sheets-Sheet 1.

J. McALLISTER. OPPSETTING DEVICE FOR SAWMILL GARRIAGES.

No. 545,303. Patented Aug. 27,1895.

I F k .fimvewtoz WMWQ ammubfw mrwm 2 Sheets-Sheet 2.

(No Model.)

J. MQALLISTERG OFFSETTING DEVICE FOR SAWMILL GARRIAGES.

No. 545,303. Patented Aug. 27, 1895.

wuawtoz views.

UNITED STATES PATENT OFFICE,

JAMES MCALLISTER, OF SOUTH MANISTIQUE, MICHIGAN, ASSIGNOR OF ONE- HALF TO A. O. HUBBELL, OF SAME PLACE.

OFFSETTING DEVICE FOR SAWMILL-CARRIAGES.

SPECIFICATION forming part of Letters Patent No. 545,303, dated August 27, 1895.

Application filed August 1,1894. Serial No. 519,201. (No model.)

To all whom, it may concern.-

Be it known that I, JAMES MCALLISTER, a resident of South Manistique, in the county of Schoolcraft and State of Michigan, have invented certain new and useful Improvements in Ofi'setting Devices for Sawmill-Carriages; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appcrtains to make and use the same.

My invention relates to an improvement in offsetting devices for sawmill-carriages, the object of the invention being to produce simple and efficient devices whereby to offset the carriage automatically from the axle or axles of the carriage.

A further object is to produce devices for the purpose which shall comprise but few parts, which shall be sure and automatic in operation, which can be readily, quickly, and easily adjusted, and which shall be effectual in every respect in the performance of their functions.

\Vith these objects in view the invention consists in certain novel features of construction and combinations and arrangements of parts, as hereinafter set forth, and pointed out in the claims.

In the accompanying drawings, Figure l is a plan view illustrating my improvements. Figs. 2 and 3 are enlarged detail sectional Figs. i. and 5 are views of certain details.

A represents a sawmillcarriage having axles a a b b, on which the usual wheels are mounted, and on said axles the frame or carriage is adapted to have a limited lateral movement, On the axles a, a my improved friction devices are located, and the device on each axle a a being of the same construction a detailed description of one will suffice for both. In fact, one of these devices would in most cases be sufficient.

B B represent two boxes, preferably of castiron, which are recessed on their inner faces, so as to produce, when placed together, an opening 0. The boxes B B are located between two plates (1 cl, which, together with bolts 2 e connecting said plates, constitute a frame for said boxes. The boxes are made with sockets ff, each box preferably being made with two such sockets, and in these sockets strong springs g g are located, one end of each spring bearing against the bottom of v the socket and the other end against'one of the plates cl. Theinner recessed faces of the boxes B B are faced with segments of wood and leather h, adapted to engage a collar or sleeve 71, secured to the axle, said collar or sleeve being made in two parts and provided with flanges h, which overlap the facing h of wood and leather. The friction device or devices thus produced are connected with a longitudinally-movable bar 0 by means of pit- Inen j. The bar 0 is pivotally connected, preferably at both ends, with one arm of bellcrank levers D D, said bell-crank levers being pivotally connected to brackets D, secured to the cross-bars k of the carriage. The arm Zof each bell-crank lever is provided with pinsl', which enter recesses made in the adjacent edges of two collars m, mounted loosely on the respective axles b. At the respective sides of each collar m collars m are secured to the shaft or axle to prevent lateral movement of the collars m on the axle. The collars m are arranged in pairs, so as to prevent lost motion.

From the construction and arrangement of parts above described it will be seen that when the carriage begins to move the collars or sleeves i on the axles a a will be clutched by the faces h of the boxes B, and said boxes will turn with the axle, thereby causing the bar C to move longitudinally, which motion of the barC will be imparted to the bell-crank levers D, and the turning of the latter (being connected with the axles b b) will cause the carriage to be offset a distance limited by suitable stops on the axles. When the carriage shall have been offset to the full extent permitted by said stops, the collar or sleeve 2' will rotate in the friction device until the motion of the carriage is reversed, when the carriage will be offset in the opposite direction in the same manner as above described.

My improved friction device can be very easily adjusted by adjusting the face-plates against which the springs g bear. The devices will be operated accurately and effectually to ofiset the carriage with a heavy or alight log thereon. My improvements are very simple of construction of my invention without de parting from the spirit thereof or limiting its scope, and hence I do not wish to limit myself to the precise details of construction herein set forth; but

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination with the frame of a saw mill carriage and axles, of a friction device mounted on and capable of turning a limited distance with one of said axles, said friction device comprising two boxes having a lining of soft material to produce a gripping surface, two heads or plates, connecting devices between said heads or plates adjustable and springs bearing against said heads or plates and boxes, and a connection between said friction device and a part independent of said frame, substantially as set forth.

2. The combination with the frame of asaw mill carriage and an axle, of a collar mounted on and capable of turning a limited degree with said axle, two boxes having a lining of soft material to grip said collar, plates bearing against said boxes, rods and nuts connecting said plates, said boxes being made with sockets, springs in said sockets, said springs hearing at one end against the bottom of said sockets and at their other ends against said plates, and a connection between said boxes and a part independent of said frame, whereby when the carriage is first moved said frame will be offset automatically, substantially as set forth.

3. The combination with the frame of a saw mill carriage and an axle, of a sectional collar comprising segments of cylinders secured on said axle, a friction device adapted to grip said collar, a bar connected with said friction device,a bell-crank-lever pivoted to the frame and to said bar, collars arranged in pairs on another axle, and connected with said bell crank lever and means for preventing said collars from moving laterally-on the axle, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

JAS. MCALLISTER.

Witnesses:

V. P. OHAPPEL, A. O. HUBBELL. 

